Chemical examination of jalap / by Frederick B. Power and Harold Rogerson.

  • Frederick Belding Power
Date:
[1910]
Catalogue details

Licence: Attribution 4.0 International (CC BY 4.0)

Credit: Chemical examination of jalap / by Frederick B. Power and Harold Rogerson. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    0.1148 of the air-dried substance, when heated at no0, lost 0.0054 HsO. H20 = 4.7. 0.1094 of anhydrous substance gave 0.3360 C02 and 0.1180 H20. C = 83.8; H = 12.0. C27H<60, HjO requires H20 = 4.5 per cent. C27H480 requires C = 83.9; H = 11.9 per cent. The substance thus agrees in composition with a phytosterol, and it gave the color reactions yielded by this class of substances. The optical rotatory power of the phytosterol was determined with the following result: 0.1349 of anhydrous substance, dissolved in 25 cc. of chloroform, gave in a 2 dcm. tube aD —o°21/, whence [a]D —32.40. A small amount of the phytosterol was converted into its acetate, which separated from its solution in acetic anhydride in leaflets, melting at 119-120°. The mother liquor from the phytosterol was evaporated, and the residue distilled under 15 mm. pressure, when the following fractions were eventually obtained: (I) Below 180°; (II) 180-190°; (III) 190- 200°; (IV) 200-225°; (V) 225-250°; (VI) 250-300°; (VII) 300-320°/i5 mm. The first four of these fractions contained a crystalline solid. This wras collected and recrystallized several times, first from light petroleum and then from ethyl acetate. It was thus obtained in small leaflets, melting at 50-51°, and was analyzed. 0.1114 gave 0.3230 C02 and 0.1434 H20. C = 79-i; H = 14-3- CjgH^O requires C = 79.3; H = 14.1 percent. This substance was thus identified as cetyl alcohol. The above-mentioned fractions (V) and (VI) were of an oily nature, and yielded nothing definite, whereas fraction (VII), on standing for a long time, deposited a small amount of a crystalline substance. This was separated, and recrystallized from ethyl acetate, when it formed glistening leaflets, melting at 56-57°. It yielded color reactions similar to those given by the phytosterols. After further crystallization from ethyl acetate, and finally from absolute alcohol, its melting point and properties remained unchanged. The substance was then analyzed. 0.0986 gave 0.2906 C02 and 0.1230 H20. C = 80.4; H = 13.9. CI8H360 requires C = 80.6; H = 13.4 percent. The composition of this substance is thus seen to agree with the formula C18H3U0, and, as it differs in its properties from any substance of this formula which has hitherto been described, it would appear to be a new compound. The amount of substance, however, was too small to admit of this conclusion being confirmed. The liquid portion of fraction (VII), from which the above-described solid had been separated, was stirred with slightly diluted alcohol, when